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DESI-DR1 $3 \times 2$-pt analysis: consistent cosmology across weak lensing surveys

A. Porredon, C. Blake, J. U. Lange, N. Emas, J. Aguilar, S. Ahlen, A. Bera, D. Bianchi, D. Brooks, F. J. Castander, T. Claybaugh, J. Coloma Nadal, A. Cuceu, K. S. Dawson, A. de la Macorra, Biprateep Dey, P. Doel, A. Elliott, S. Ferraro, A. Font-Ribera, J. E. Forero-Romero, C. Garcia-Quintero, E. Gaztañaga, S. Gontcho A Gontcho, G. Gutierrez, J. Guy, B. Hadzhiyska, H. K. Herrera-Alcantar, S. Heydenreich, K. Honscheid, C. Howlett, D. Huterer, M. Ishak, S. Joudaki, R. Joyce, D. Kirkby, A. Kremin, A. Krolewski, O. Lahav, C. Lamman, M. Landriau, L. Le Guillou, A. Leauthaud, M. E. Levi, M. Manera, A. Meisner, R. Miquel, S. Nadathur, J. A. Newman, G. Niz, N. Palanque-Delabrouille, W. J. Percival, C. Poppett, F. Prada, I. Pérez-Ràfols, A. Robertson, G. Rossi, R. Ruggeri, E. Sanchez, C. Saulder, D. Schlegel, M. Schubnell, A. Semenaite, H. Seo, J. Silber, A. Souki, D. Sprayberry, G. Tarlé, M. Vargas-Magaña, B. A. Weaver, C. Zhou, R. Zhou, H. Zou

TL;DR

This work presents a joint 3×2-pt cosmological analysis combining DESI-DR1 galaxy clustering with WL data from DES-Y3, KiDS-1000, and HSC-Y3. A unified modelling pipeline, analytical cross-covariance, and a blinding scheme enable robust constraints on $S_8$, $\,\Omega_m$, and $\sigma_8$ under ΛCDM and, separately, on $w$ in wCDM, with results showing mutual consistency across surveys and compatibility with Planck within ~1.5–2σ. The analysis demonstrates how spectroscopic clustering and weak lensing cross-correlations break degeneracies and mitigate systematics such as intrinsic alignments and baryonic feedback, while validating scale cuts and covariance models. These joint constraints pave the way for future DESI data releases and cross-survey cosmology in the Stage-IV era, including broader cross-correlations with upcoming surveys. The study highlights subtle dependencies on modelling choices (e.g., IA model, baryonic physics) and confirms that a cohesive, blinded framework yields stable cosmological inferences.

Abstract

We present a joint cosmological analysis of projected galaxy clustering observations from the Dark Energy Spectroscopic Instrument Data Release 1 (DESI-DR1), and overlapping weak gravitational lensing observations from three datasets: the Kilo-Degree Survey (KiDS-1000), the Dark Energy Survey (DES-Y3), and the Hyper-Suprime-Cam Survey (HSC-Y3). This combination of large-scale structure probes allows us to measure a set of $3 \times 2$-pt correlation functions, breaking the degeneracies between parameters in cosmological fits to individual observables. We obtain mutually-consistent constraints on the parameter $S_8 = σ_8 \sqrt{Ω_{\rm m}/0.3} = 0.786^{+0.022}_{-0.019}$ from the combination of DESI-DR1 and DES-Y3, $S_8 = 0.760^{+0.020}_{-0.018}$ from KiDS-1000, and $S_8 = 0.771^{+0.026}_{-0.027}$ from HSC-Y3. These parameter determinations are consistent with fits to the Planck Cosmic Microwave Background dataset, albeit with $1.5-2σ$ lower values in the $S_8-Ω_{\rm m}$ plane. We perform our analysis with a unified pipeline tailored to the requirements of each cosmic shear survey, which self-consistently determines cosmological and astrophysical parameters. We generate an analytical covariance matrix for the correlation data including all cross-covariances between probes, and we design a new blinding procedure to safeguard our analysis against confirmation bias, whilst leaving goodness-of-fit statistics unchanged. Our study is part of a suite of papers that present joint cosmological analyses of DESI-DR1 and weak gravitational lensing datasets.

DESI-DR1 $3 \times 2$-pt analysis: consistent cosmology across weak lensing surveys

TL;DR

This work presents a joint 3×2-pt cosmological analysis combining DESI-DR1 galaxy clustering with WL data from DES-Y3, KiDS-1000, and HSC-Y3. A unified modelling pipeline, analytical cross-covariance, and a blinding scheme enable robust constraints on , , and under ΛCDM and, separately, on in wCDM, with results showing mutual consistency across surveys and compatibility with Planck within ~1.5–2σ. The analysis demonstrates how spectroscopic clustering and weak lensing cross-correlations break degeneracies and mitigate systematics such as intrinsic alignments and baryonic feedback, while validating scale cuts and covariance models. These joint constraints pave the way for future DESI data releases and cross-survey cosmology in the Stage-IV era, including broader cross-correlations with upcoming surveys. The study highlights subtle dependencies on modelling choices (e.g., IA model, baryonic physics) and confirms that a cohesive, blinded framework yields stable cosmological inferences.

Abstract

We present a joint cosmological analysis of projected galaxy clustering observations from the Dark Energy Spectroscopic Instrument Data Release 1 (DESI-DR1), and overlapping weak gravitational lensing observations from three datasets: the Kilo-Degree Survey (KiDS-1000), the Dark Energy Survey (DES-Y3), and the Hyper-Suprime-Cam Survey (HSC-Y3). This combination of large-scale structure probes allows us to measure a set of -pt correlation functions, breaking the degeneracies between parameters in cosmological fits to individual observables. We obtain mutually-consistent constraints on the parameter from the combination of DESI-DR1 and DES-Y3, from KiDS-1000, and from HSC-Y3. These parameter determinations are consistent with fits to the Planck Cosmic Microwave Background dataset, albeit with lower values in the plane. We perform our analysis with a unified pipeline tailored to the requirements of each cosmic shear survey, which self-consistently determines cosmological and astrophysical parameters. We generate an analytical covariance matrix for the correlation data including all cross-covariances between probes, and we design a new blinding procedure to safeguard our analysis against confirmation bias, whilst leaving goodness-of-fit statistics unchanged. Our study is part of a suite of papers that present joint cosmological analyses of DESI-DR1 and weak gravitational lensing datasets.

Paper Structure

This paper contains 29 sections, 30 equations, 15 figures, 6 tables.

Table of Contents

  1. Introduction
  2. Data
  3. DESI Data Release 1
  4. DES Year 3
  5. KiDS-1000
  6. HSC Year 3
  7. Methodology
  8. Modelling
  9. Cosmic shear
  10. Galaxy-galaxy lensing
  11. Projected galaxy clustering
  12. Measurements
  13. Parametrisation and priors
  14. Photometric redshifts
  15. Shear calibration
  16. ...and 14 more sections

Figures (15)

  • Figure 1: Marginalised constraints on $\Omega_\mathrm{m}$, $\sigma_8$, and $S_8$ in $\Lambda$CDM for DES-Y3 cosmic shear (solid yellow), the combination of galaxy-galaxy lensing and projected galaxy clustering from DESI-DR1 (dashed blue), and the $3\times2$-pt combination (solid green).
  • Figure 2: Marginalised constraints on $\Omega_\mathrm{m}$, $\sigma_8$, and $S_8$ in $\Lambda$CDM for KiDS-1000 cosmic shear (solid yellow), the combination of galaxy-galaxy lensing and projected galaxy clustering from DESI-DR1 (dashed blue), and the $3\times2$-pt combination (solid green).
  • Figure 3: Marginalised constraints on $\Omega_\mathrm{m}$, $\sigma_8$, and $S_8$ in $\Lambda$CDM for HSC-Y3 cosmic shear (solid yellow), the combination of galaxy-galaxy lensing and projected galaxy clustering from DESI-DR1 (dashed blue), and the $3\times2$-pt combination (solid green).
  • Figure 4: Marginalised constraints on $\Omega_\mathrm{m}$, $S_8$, and $w$ in $w$CDM from the $3\times2$-pt combination of DESI-DR1 projected galaxy clustering and weak lensing data from DES-Y3 (solid yellow), KiDS-1000 (dashed blue), and HSC-Y3 (dash-dotted green).
  • Figure 5: Comparison of 68% C.I. constraints on $S_8$, $\Omega_\mathrm{m}$, and $\sigma_8$, in $\Lambda$CDM from the $3\times2$-pt combination of DESI-DR1 projected galaxy clustering and weak lensing data from DES-Y3, KiDS-1000, and HSC-Y3 for several variation of analysis choices.
  • ...and 10 more figures